CF1616F Tricolor Triangles
Description
You are given a simple undirected graph with $ n $ vertices and $ m $ edges. Edge $ i $ is colored in the color $ c_i $ , which is either $ 1 $ , $ 2 $ , or $ 3 $ , or left uncolored (in this case, $ c_i = -1 $ ).
You need to color all of the uncolored edges in such a way that for any three pairwise adjacent vertices $ 1 \leq a < b < c \leq n $ , the colors of the edges $ a \leftrightarrow b $ , $ b \leftrightarrow c $ , and $ a \leftrightarrow c $ are either pairwise different, or all equal. In case no such coloring exists, you need to determine that.
Input Format
The first line of input contains one integer $ t $ ( $ 1 \leq t \leq 10 $ ): the number of test cases.
The following lines contain the description of the test cases.
In the first line you are given two integers $ n $ and $ m $ ( $ 3 \leq n \leq 64 $ , $ 0 \leq m \leq \min(256, \frac{n(n-1)}{2}) $ ): the number of vertices and edges in the graph.
Each of the next $ m $ lines contains three integers $ a_i $ , $ b_i $ , and $ c_i $ ( $ 1 \leq a_i, b_i \leq n $ , $ a_i \ne b_i $ , $ c_i $ is either $ -1 $ , $ 1 $ , $ 2 $ , or $ 3 $ ), denoting an edge between $ a_i $ and $ b_i $ with color $ c_i $ . It is guaranteed that no two edges share the same endpoints.
Output Format
For each test case, print $ m $ integers $ d_1, d_2, \ldots, d_m $ , where $ d_i $ is the color of the $ i $ -th edge in your final coloring. If there is no valid way to finish the coloring, print $ -1 $ .